


Boy Toy

by wretchedhag



Series: FGO/Kinktober [10]
Category: Fate/Grand Order
Genre: Dom/sub Undertones, Eye Licking, F/M, Mild Blood Drinking, Sexual Tension, Teasing, mildly dubious consent tag just in case
Language: English
Status: Completed
Published: 2021-01-25
Updated: 2021-01-25
Packaged: 2021-03-17 09:29:00
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,860
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28972119
Author URL: https://archiveofourown.org/users/wretchedhag/pseuds/wretchedhag
Summary: Shuten sets her sights on Izou as her latest plaything.Or, Izou's life becomes increasingly complicated due to a certain oni.
Relationships: Shuten-Douji and Okada Izou
Series: FGO/Kinktober [10]
Series URL: https://archiveofourown.org/series/1956010
Comments: 2
Kudos: 10





	Boy Toy

**Author's Note:**

> this was for the prompt "humiliation", although it's more of izou getting his chain yanked rather than humiliation in the usual sense. shuten and izou aren't necessarily a ship for me so much as i like the possibility of their interactions, but there's no romantic connotations and they're not going to go all the way together. i just think shuten messing with him and izou being confused by it is sexy, lol. also, this whole fic--but the first and final scenarios especially--was inspired by fanart i've seen on pixiv. i'm not going to be linking to the works here since i don't know if the artists would want their works linked to on an external site, but i felt like i should be transparent that the ideas aren't entirely original. enjoy!

Neither humans nor oni can change their natures. That’s an immutable fact, like the placement of the stars in the night sky or the moon’s pull on the tides. Shuten-Douji, for her part, has never been one to deny her own nature. 

She can’t help but want to toy with people, to push their buttons and see how far she can rile them up. Especially when it comes to humans, or more accurately, nowadays, Heroic Spirits who were once humans. And now her sights have landed on the little manslayer who terrorized Kyoto long after her own heyday. 

Part of Shuten’s interest stems from the fact that Izou reminds her a bit of that particular golden boy; their naivety, earnestness, and simple attitudes are all rather similar. And he does have a brutal strength that Shuten likes (she has no time for weaklings, after all). Perhaps most importantly, there’s the fact that Shuten has seen how easy Izou is to rile up and his amusing reactions which follow. Anyone would find it irresistible to tease a boy like that—can she really be blamed for wanting to play with him at his expense? 

The first time that it happens is after a particularly rowdy drinking party. Shuten is the last one standing, as usual. The other Servants either left in the early stages, were forcibly removed by more responsible members of Chaldea, or passed out in various stages of drunkenness. The latter is the case for Izou, who lies asleep on the floor.

“My, my, what do we have here…?” Shuten says to herself as she saunters over and stands above Izou’s prone form.

His clothing had come loose at some point earlier in the night, and his scarf lies forgotten on the floor; his kosode is pulled open to the waist with his obi all but useless. Thanks to his state of undress, Shuten’s attention had been caught by the newly exposed circlet of discolored scar tissue around Izou’s neck. A smile tugs at her lips as Shuten touches the choker of her own clothing. 

“Who would have thought we have something in common, little manslayer.” 

Shuten drops down and kneels over Izou. This close, she can smell the scent of his blood underneath the aroma of alcohol. It whets her appetite. 

She runs her hand over the muscular swell of Izou’s chest and up to his throat. Her fingers ghost over the scar tissue to pause at his carotid artery. She feels the steady beats of his heart and the pumping of his blood just under the surface. Shuten bows her head and brings her teeth against the thin, delicate skin. 

It’s just her nature as an oni.

🙦

Izou is in the space between sleep and wakefulness. As his consciousness floats in darkness, he slowly becomes aware of a sucking sound close to his head. He tries to shift his position, only to find a weight on top of him and that there’s a warm, wet sensation against his throat. 

“What the hell?!” Izou shrieks as he opens his eyes. 

Izou’s alcohol addled brain works overtime to process what’s happening and what he’s seeing. Shuten is sitting astride his chest with one hand cupping the back of his head and the other hand holding a sakazuki. Her mouth and chin are messy with crimson blood, which Izou soon realizes came from his own neck. When he looks down, there’s a stream of fresh blood flowing down his chest. 

“Mmm, good morning.” Shuten nonchalantly takes a drink from her cup. “I hope you had a pleasant dream.”

Izou stutters, too shocked to form a proper sentence. Perhaps ironically, his mouth is dry, and his throat burns like sandpaper. Izou’s hand trembles as he raises it up to his throat and presses against the place where Shuten had been drinking. His face must have paled as he felt the bites because Shuten clicks her tongue. 

“Don’t get so worked up over a little love bite. Besides, it’s already healing up quite nicely.” Shuten chides. 

She’s right. Underneath his palm, Izou can already feel the bite closing over, the skin stitching itself back together, all thanks to Chaldea’s constant stream of Mana. But that doesn’t make him feel much better about the fact that Shuten was drinking her fill of his blood just moments prior. 

“Get offa me,” Izou growls and tries to shove Shuten away with his arm. 

“Ooh, giving orders now, are we?” She smiles, her bloodstained canines standing out sharply. 

Shuten runs her tongue over her teeth and it sends a shiver up Izou’s spine. Not of fear, but… something else. He doesn’t want to think about it or the implications of that right now. 

Shuten nimbly gets to her feet and steps to the side. Amusement dances in her eyes as she watches Izou snatch up his scarf and quickly wraps it around his neck. He shoots off a glare, but it doesn’t have much venom to it as he’d hoped. 

🙦

Maybe she had started out playing a little too rough. But Izou’s reaction to her had been delightful, especially when he tried to shove her off. There’s nothing more amusing than a small, yappy dog trying to act like a large, fearsome wolf. And his response to her licking her teeth did not escape her notice—she’ll absolutely be following that thread more. 

Izou is more cautious around Shuten after that, but she isn’t going to let him run away from her. She makes sure to cross his path, whether that be flashing a completely wholesome smile in the hall or sidling up to his chair in the cafeteria. When Master needs Assassins for missions, Shuten is sure to volunteer her services. She pokes and prods Izou with suggestive inflections and gestures, and relishes how she makes him squirm. 

She really does love adorable, simpleminded men. Especially ones who contribute so readily to their own oblivion. It’s a delight to Shuten that Izou can’t control his vices, and it isn’t long before they’re in a similar situation as their first encounter. 

Anyone else would be put-off from drinking for a long time after waking up to an oni indulging on their blood, yet Izou returns to the drinking group in no time. He keeps close to Yan Qing and the elder Li Shuwen, but Shuten doesn’t mind and bides her time. When he glances at Shuten from across the room, she raises her cup and flashes a toothy smile.

As the night goes on, groups naturally shift and dissolve and the opportunity Shuten had been waiting for arrives. With a bottle of sake in her hand, Shuten approaches Izou who is now sitting alone. He fixes her with a look of suspicion as she comes to a stop in front of him.

“Care for another round?” She asks.

Izou clicks his tongue and turns his head away.

“The silent treatment, is it? How cruel.”

Shuten sets the bottle aside and leans down so that she’s in Izou’s personal space. She brings her mouth to Izou’s ear and blows lightly. Izou flinches and Shuten chuckles softly in response.

“You’ll hurt a girl’s feelings like that if you’re not careful,” Shuten whispers.

“Are you makin’ fun of me?”

“Does it seem that way? I’m just trying to get to know a Servant who’s like myself.”

That made him look at her.

“Like you?”

Shuten smiles benignly, “Yes, we’re not so different. There are the simple things, like enjoying good alcohol and entertainment. But what really makes us the same is that you enjoy fighting and killing as much as me, don’t you? It makes you excited, gets your blood pumping, just the same as holding a lover, doesn’t it?”

Izou is staring at her intently, brows furrowed, and Shuten can practically see the gears turning. He opens his mouth like he’s going to say something, but then changes his mind. Shuten brings up her hand and drags her thumb along Izou’s bottom lip.

“You don’t have to worry your head about giving me an answer that way, little manslayer. Instead, how about we work up a sweat together and you let your body answer for you?”

“...S-Shut up,” Izou mumbles and extricates himself from Shuten’s grasp. “I’m outta the mood for drinking.”

He walks away without a backwards glance at her. Probably because he didn’t want Shuten to see how his face was flushed pink to the ears, but it was a little late for that. Shuten hums happily as she picks back up the sake bottle and takes a swig from it. 

🙦

Izou has noticed that he’s become the latest object of Shuten’s attention, though he doesn’t understand why. Then again, he’s never been very good at divining the intentions of others. But he doesn’t believe for a second that she just wants to “get to know” him.

Rather, Izou is more preoccupied with trying to decipher his own feelings on the matter. He hates that he ran away from her last time, but he didn’t want her to know that he was getting excited by the way she was whispering in his ear and putting her fingers on his mouth. And that spike of arousal he felt when Shuten ran her tongue over her teeth still weighs heavily on his mind. 

Izou had never felt any sort of attraction to Shuten prior to all of this. But after that incident and now with the way that she keeps inserting herself into his space, he can’t help but notice that he’s developed a bit of a strange fixation. There’s just something about the breathy, singsong way she speaks, the sensual way she moves, and the sweet alcoholic scent that hangs around her.

It frustrates him to be thrown off-kilter by her, and it frustrates him even more to not understand what he’s feeling in response. It’s probably lust, but he’s never been so confused by a woman before. But the thought of sex with Shuten doesn’t seem too bad.

Especially considering that when he’s alone in his room, that first time keeps coming back to him. He’ll put his hand to his neck and a certain warmth will begin to stir deep inside of him. Since he wasn’t awake for it, he can only imagine how Shuten laid against him, cradled his head while breaking the skin of his throat, then sucked and lapped at the blood that spilled out…

He needs to stop trying to think so much.

🙦

Shuten is pleased when Izou finally takes up her offer to spar with her. She’s come to realize that Izou is the type you can lead along and toy with, but if you want him to do something you have to make him feel like it was his own idea. And since he came to her without any further prodding on her part, that means her words have stuck in his mind, which is exactly what she was hoping for. 

While she would have preferred to take a quick Rayshift for this, this new Chaldea has a lack of easily manipulatable staff members who would let her do that. Or maybe it’s more accurate to say that Sion and her Captain are just too perceptive. At any rate, a simple simulation will work fine, even if it’s not nearly as fun. 

During their fight, Izou comes at her as brutally as she had hoped for. And while there’s not much refinement to his movements, Shuten can appreciate a similarly bloodthirsty attitude to her own. 

“Careful,” Shuten taunts as she narrowly turns out of the way of Izou’s blade, “that could hurt someone!”

“Tch.”

Unfortunately for Izou, Shuten isn’t going to stay in one place and fight him like a swordsman. She flits around the field, dodging and sending out blows of her own. Izou grows more and more frustrated and switches between swordplay styles—those that he was trained in as well as those that he observed from other Chaldean Servants—looking for one that will land a decisive blow on Shuten. She finds it incredibly delightful; now here’s a puppy who’s trying to prove himself. 

“You’re imitating that cow?” She asks upon seeing Izou shift into Raikou’s stance. “You should know, she wasn’t able to cut me down without resorting to dirty tricks.”

Although, it’s just about time to reveal her own ace up her sleeve. Shuten jumps away and materializes her sakazuki to take a sip of its liquor and activate her Intoxicating Aroma of Fruits Skill. She's never used it on Izou before, but a little shove on the path one was already going down never hurt anyone. The Skill affects Izou immediately and stops him in his tracks. A full-body shiver wracks him and color begins to rise in his cheeks.

“Ah, Ahh… What was that... about dirty tricks…?” Izou huffs.

“Did you forget? I’m an oni. We’re not bound by silly things like a warrior’s honor.”

Izou glares and swings out wildly with his sword, but Shuten easily steps out of range with a laugh. Not a second later, Izou drops to his knees and his sword clatters to the ground. Shuten kicks it aside as she strolls forward and places her hand underneath Izou’s jaw to tilt his head up and look at her.

“You can try to act tough, but you’re not so scary like this, puppy,” Shuten coos.

🙦

Izou’s entire body feels hot, like he’s being consumed from the inside out. He can’t help how he’s shaking or how his breath is coming out in short gasps. His head feels hazy, too, like every thought is melting away before he can string them together.

His world has narrowed to the singular points of his own body and Shuten herself. She encompasses his entire field of vision—no, more like she encompasses all his senses. Any point on his body that she touches burns hotter and he leans into her touch, wanting more of it.

Izou tries to say something, to swear at her, but all that he can manage is a series of disconnected syllables. That just seems to add to Shuten’s amusement. With one hand still holding his jaw, she uses the other to push his bangs back and away from his face.

“What a delicious expression you’re making. And these eyes of yours… I prefer blue, but your golden ones are lovely. Like egg yolk over rice.” Shuten licks her lips. “It makes you want to just _slurp_ them right up.” 

Izou’s eyes go wide when Shuten opens her mouth and leans in close. Her breath feels cool on his heated skin, and his own breath as Shuten licks a stripe over the cornea of his normally hidden right eye. It’s an odd sensation, but not entirely unpleasant. Shuten pulls back and looks Izou up and down.

“Oh, my, what’s this?” Shuten asks. 

Izou follows her line of sight and burns with embarrassment when he sees how the front of his hakama is tented.

“N-no way…” He sputters, finally finding his voice.

“Your body is much more honest than you are,” Shuten comments with a smile.

Shuten lifts her leg, presses the ball of her foot to the tip of Izou’s erection, and slowly drags it down the length. A sensation like lightning shoots up his spine that makes him cry out and causes his hips to buck up into her touch. Because of that damnable Skill of hers, every little touch is so much more intense than it would be otherwise. 

“Won’t you tell me _aaall_ about that exquisite pleasure you’re feeling?” Shuten murmurs.

Izou shakes his head and presses his lips together in a futile attempt to muffle himself. He’s so overwhelmed, embarrassment and pleasure mixing into something nearly unbearable, that tears are beginning to gather at the corners of his eyes.

“Don’t get shy on me now, puppy. There’s no reason to be so embarrassed about a little intimacy.”

Shuten puts her hands on Izou’s shoulders and shoves so that he falls onto the floor. She quickly straddles his hips and wraps her arm’s around his neck, her fingers tangling in his hair. Shuten grinds her hips down and nips Izou's earlobe with her teeth.

“Be a good boy for me, won’t you?”

Izou can’t handle anymore. He wants to melt underneath Shuten’s ministrations, and for her to drink all of him up. He turns his head to meet her mouth with his own—

“Shuten?” Master’s voice rings out suddenly and shatters the fantasy between them. “Izou? Are you two still in here?”

With a sigh, Shuten disentangles herself and stands up. As soon as she steps out of Izou’s immediate proximity, he begins to feel his head start to clear up. Shuten looks towards the door where Master is waiting then back at Izou.

“Let’s play again sometime, puppy.” 

Shuten is off with a wink and a wave. Izou watches her walk away for a few moments before he flops backwards onto the floor, exhausted. His heart is still pounding, and his head is still spinning, but that’s all something to figure out later.


End file.
